I don't have a board in front of me, but from memory T3 Pri:2 and T2 Pri:2 should be jumpered to T3 Pri:1 and T2 Pri:1 for triode operation, or T3 Pri:3 and T2 Pri:3 for pentode operation. It is much easier to get the amp running in triode configuration.

I've been running my SSE in pentode mode for more than a year with good results, mostly with low screen voltage sweep / rf tubes, with good results. I have also used the EL34 with good results, albeit at relatively low screen voltages.

Be advised that, imo, pentode mode does require more negative feedback than the onboard cathode feedback can provide, at least in my setup. Without negative feedback, the frequency response will be skewed to favor the high frequencies,

More can be found in the 6146 in the SSE thread, if you are interested.

Thanks, i'm gonna start with triode mode to get the amp running. I'm doing the basic configuration with a 375-0-375 power transformer, so i could get a >400 V B+, perhaps thats not provide low screen voltage, what's your low screen voltage and your B+?